ORGANS OF BESPIBATION AND VOICE -j-V*
bone by the thyro-hyoid membrane, which :* perforated by the communications betwc-en the air sac and 3arynge.u ventricles. The cricoid cartilage and crico-thyroid membrane are as in Man. The epiglottis is shipf ,1 as
in Man, but it does not rise verv fullv above the s:nal!
* * *
aryteno-epiglottic folds. The arytenoid cartilages are in many ways similar to those in Man: their processes are not greatly elongated, and they form parts of arcs. The cuneiform and corniculate cartilages are nJnule, but definite. The joints between the cartilages are a- in Man. In the (rorilla the thyroid cartilage i? smaller than in Man, and its lower border is not incised deeply as in the Chimpanzee. The cricoid cartilage is larger than in Man, and its anterior part is more slender than in the Chimpanzee. The arytenoid cartilages have long processes, but the cuneiform and corniculate cartilages are either absent or represented by fibrous rather than cartilaginous tissue In the Orang the thyroid cartilage is larger and the cricoid cartilage is smaller than in Map, the arytenoid cartilages have three branches, but there are no cuneiform cartilages. The Gibbons have certain peculiarities, which are associated with their great vocal powers. The thyroid cartilage is large relatively to the cricoid, and differs from that of all other Apes in the possession of two inferior cornua. The anterior part of the cricoid cartilage is narrow and the posterior part is massive. The posterior part of the laryngeal cavity is deeper than the anterior part, and the arytenoid cartilages are lower than the vocal cords. Laryngeal Muscles.*"In the Chimpanzee the
* Accounts of ihe larynx and its muscles haye been given in papers 50, 53, 69, 122, 162, 199, 201, 259, 330, 357» 399» 4°*> 4»-